Interdisciplinary teaching is vital for equipping students to address complex public health challenges. This study explores teachers' reflections on interdisciplinary teaching in Singapore's undergraduate public health programmes, examining facilitators and barriers to its implementation. Using surveys and in-depth interviews, we gathered diverse insights from teachers. Quantitative results revealed a significant positive association between interdisciplinary teaching frequency, and willingness for further integration, and non-significant associations for perceptions on knowledge and importance of integration. Notably, participants' satisfaction with the current state of interdisciplinary learning in the public health curriculum or during internship supervision was low, although this finding was not significant. Qualitative findings highlighted successful practices, such as fostering core competencies through cross-disciplinary efforts, alongside challenges like collaboration difficulties, faculty specialisation, and limited institutional support. These insights underscore the need for clear guidelines and robust institutional frameworks to strengthen interdisciplinary teaching. Addressing these gaps can help institutions foster an environment where teachers deliver integrated education that prepares students for public health complexities. This study contributes to the literature on interdisciplinary teaching in higher education and advocates for cohesive, reflective approaches that support collective transformation in academic practice.